Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Engineering Black Gold, as Light as the Bones of Birds

01.04.2016

A new research affiliated with UNIST, Korea, suggests a new material that is more solid and 30% lighter than standard gold.

A team of Korean research team led by Professor Ju-Young Kim (School of Materials Science and Engineering) of Ulsan National Institute of Science and Technology (UNIST), South Korea, has recently announced that they have successfully developed a way to fabricate an ultralight, high-dense nanoporous gold (np-Au).


A research team developed the nanoporous structure after strengthening with ball milling technique and producing silver only with dealloying technique.

Copyright : UNIST

In a new paper, published in Nano Letters on March 22, the team reported that this newly developed material, which they have dubbed "Black Gold" is twice more solid and 30% lighter than standard gold.

According to Prof. Kim, "This particular nanoporous gold sample has a 100,000 times wider surface when compared to standard gold. Moreover, due to its chemically stablity, it is also harmless to humans."

... more about:
»Birds »Bones »Nano »UNIST

The surfaces of np-Au are rough and the metal loses its shine and eventually turns black when they are at sizes less than 100 nanometres (nm). This is the reason that they are called "Black Gold".

In their study, the team investigated grain boundaries in nanocrystalline np-Au and found a way to overcome the weakening mechanisms of this material, thereby suggesting its usefulness.

The team used a ball milling technique to increase the flexural strength of the three gold-silver precursor alloys. Then, using free corrosion dealloying of silver from gold-silver alloys, they were able to achieve the nanoporous surface. According to the team, "The size of the pores can be controlled by the temperature and concentration of nitrate." Moreover, they also note that this crack-free nanoporous gold samples are reported to exhibit excellent durability in three-point bending tests.

Prof. Kim's team notes, "Ball-milled np-Au has a much greater density of two-dimensional defects than annealed and prestrained np-Au, where intergranular fracture is preferred." They continue, "Therefore, the probable existence of grain boundary opening in the highest tensile region is attributed to the flexural strength of np-Au."

They suggest that this newly developed technique can be also applied to many other metal, as the np-Au produced by this technique have shown increased strength and durability while still maintaining the good qualities of standard gold.

This means that this technique can be also used in other technologies, like catalytic-converting as observed by platinum, the automobile catalyst and palladium, the hydrogen sensor catalyst.

Journal Reference:
Eun-Ji Gwak and Ju-Young Kim. "Weakened Flexural Strength of Nanocrystalline Nanoporous Gold by Grain Refinement". Nano Lett., (2016).

Associated links

Journal information

Nano Letters

Funding information

National Research Foundation of Korea (NRF), Korean Ministry of Science, ICT & Future Planning (MSIP), KIST-UNIST partnership program

UNIST Public Relations Team | Research SEA
Further information:
http://www.researchsea.com

Further reports about: Birds Bones Nano UNIST

More articles from Materials Sciences:

nachricht Robust and functional – surface finishing by suspension spraying
19.09.2017 | Fraunhofer-Institut für Keramische Technologien und Systeme IKTS

nachricht Graphene and other carbon nanomaterials can replace scarce metals
19.09.2017 | Chalmers University of Technology

All articles from Materials Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Tiny lasers from a gallery of whispers

New technique promises tunable laser devices

Whispering gallery mode (WGM) resonators are used to make tiny micro-lasers, sensors, switches, routers and other devices. These tiny structures rely on a...

Im Focus: Ultrafast snapshots of relaxing electrons in solids

Using ultrafast flashes of laser and x-ray radiation, scientists at the Max Planck Institute of Quantum Optics (Garching, Germany) took snapshots of the briefest electron motion inside a solid material to date. The electron motion lasted only 750 billionths of the billionth of a second before it fainted, setting a new record of human capability to capture ultrafast processes inside solids!

When x-rays shine onto solid materials or large molecules, an electron is pushed away from its original place near the nucleus of the atom, leaving a hole...

Im Focus: Quantum Sensors Decipher Magnetic Ordering in a New Semiconducting Material

For the first time, physicists have successfully imaged spiral magnetic ordering in a multiferroic material. These materials are considered highly promising candidates for future data storage media. The researchers were able to prove their findings using unique quantum sensors that were developed at Basel University and that can analyze electromagnetic fields on the nanometer scale. The results – obtained by scientists from the University of Basel’s Department of Physics, the Swiss Nanoscience Institute, the University of Montpellier and several laboratories from University Paris-Saclay – were recently published in the journal Nature.

Multiferroics are materials that simultaneously react to electric and magnetic fields. These two properties are rarely found together, and their combined...

Im Focus: Fast, convenient & standardized: New lab innovation for automated tissue engineering & drug

MBM ScienceBridge GmbH successfully negotiated a license agreement between University Medical Center Göttingen (UMG) and the biotech company Tissue Systems Holding GmbH about commercial use of a multi-well tissue plate for automated and reliable tissue engineering & drug testing.

MBM ScienceBridge GmbH successfully negotiated a license agreement between University Medical Center Göttingen (UMG) and the biotech company Tissue Systems...

Im Focus: Silencing bacteria

HZI researchers pave the way for new agents that render hospital pathogens mute

Pathogenic bacteria are becoming resistant to common antibiotics to an ever increasing degree. One of the most difficult germs is Pseudomonas aeruginosa, a...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

“Lasers in Composites Symposium” in Aachen – from Science to Application

19.09.2017 | Event News

I-ESA 2018 – Call for Papers

12.09.2017 | Event News

EMBO at Basel Life, a new conference on current and emerging life science research

06.09.2017 | Event News

 
Latest News

Molecular Force Sensors

20.09.2017 | Life Sciences

Producing electricity during flight

20.09.2017 | Power and Electrical Engineering

Tiny lasers from a gallery of whispers

20.09.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>